%0 Journal Article %A Gurinder Kumar %A Vasudev Omprakash Sharma %A Khalid Mohamed Mansour Mohamedfaris %A Rajendran Nair %A Aman Preet Singh Sohal %T Clue to the diagnosis on chest X-ray in a child with neck swelling %D 2018 %R 10.1136/archdischild-2018-315856 %J Archives of disease in childhood - Education & practice edition %P edpract-2018-315856 %X Differentiated thyroid cancer is a rare disease in children and adolescents and manifests exclusively in the form of papillary thyroid cancer (PTC). We present a rare case of PTC who presented initially with lung symptoms and miliary nodules on chest X-ray. This case emphasises the important differential of miliary mottling of the lungs.A 7-year-old girl presented with history of neck swelling and change in voice for the past 9 months and progressively worsening dyspnoea for 5 months. She was assessed elsewhere and treated with multiple courses of antibiotics without relief, as well as levothyroxine 50 µg daily for new hypothyroidism. Her initial thyroid function tests were not available.There was a history of weight loss, but no cough or night sweats. There was no history of tuberculosis (TB) contact or environmental exposure. On examination, child was tachypnoeic, tachycardic and requiring oxygen. Her initial chest X-ray is shown in figure 1. She was initially treated as suspected TB rather than immunodeficiency with antitubercular drugs (rifampicin/isoniazid/pyrazinamide/streptomycin). Bronchoscopy was negative for TB, bacteria, fungus and malignant cells, with lung biopsy (shown in figures 2 and 3). HIV and quantiferon results were negative.Figure 1 Chest x-ray. Figure 2 H&E stain.Figure 3 Immunohistochemistry of the lung tissue.The thyroid profile done while on levothyroxine was as below:TSH: 14.7 mill IU/L (0.6–4.1).Free T3: 5.2 pmol/L (4.10–7.90).Free T4: 15.2 pmol/L (11.6–32.8).Thyroglobulin: 31 µg/L (1.40–78).TPO Ab: >600 IU/mL (normal high ≤34).Thyroglobulin Ab: >4000 (normal high ≤115).QuestionsWhat is the abnormality in the chest X-ray and possible differential diagnosis?What are the histology findings in lung biopsy depicted in light microscopy figure 2 and immunohistochemistry in figure 3?The family asks you: what is the diagnosis and treatment? Are there any side effects? What is the likely outcome? %U https://ep.bmj.com/content/edpract/early/2018/11/14/archdischild-2018-315856.full.pdf